ABSTRACT
Aim To detect the expression of miRNA-99b and mTOR in glioma tissues and to investigate the effect of miRNA-99b on the cell invasion ability of hu-man glioma cell line U251. Methods The expres-sions of miRNA-99b and mTOR mRNA in glioma tis-sues and normal brain tissues were detected by real-time PCR. After co-transfection with miRNA-99b mim-ics and wild or mutation type mTOR 3′UTR recombina-tion vector,the specific binding ability of miRNA-99b to 3′-UTR in mTOR gene was examined by luciferase gene reporter system. The expression levels of miRNA-99b,mTOR mRNA and mTOR protein in glioma cell line U251 after transfected with miRNA-99b mimics were measured by real-time PCR and Western blot,re-spectively. The cell invasion was measured by Tran-swell assay. The changes of mTOR and miRNA-99b expression levels in U251 cells after transfection with mTOR PsiCHECK were detected by real-time PCR. The correlation between the expression of miRNA-99b and prognosis was analyzed statistically. Results The expressed level of miRNA-99b was lower, and the ex-pression level of mTOR was higher in the glioma tissues than that in the normal brain tissues. The expression of miRNA-99b was up-regulated, and the expressions of mTOR mRNA and protein were down-regulated in U251 cells after transfection with miRNA-99b mimics. However, the abilities of invasion of U251 cells after transfection with miRNA-99b mimics were inhibited. The relative protein expression levels of mTOR in mTOR PsiCHECK group were significantly different from those in negative control group, but the relative expression levels of miRNA-99b had no signifi-cant difference compared with those in negative control group. Over-expression of mTOR restored the abilities of cell invasion in U251 cells, which was reduced by miRNA-99b. The Kaplan—Meier analysis and Log-Rank Test showed that there were significant differ-ences in overall survival (OS) between the miRNA-99b high-expression and low-expression group. Con-clusions The expression level of miRNA-99b is low in human glioma tissue. miRNA-99b may inhibit the cell invasion activity of glioma cell line U251 in vitro via inhibiting mTOR expression.
ABSTRACT
MISA (MicroSAtelite) software was employed to screen SSRs in 68 787 contigs of Swertia mussotii transcriptome sequences. 5 610 SSRs were distributed in 5 099 contigs which accounted for 7.41% of 68 787 contigs. There are 220 kinds of SSR motifs existing in S. mussotii transcriptome. On average, SSRs occurred every 12.60 kb in length. In the SSRs, the tri-nucleotide repeat motif was the most abundant (45.99%), followed by the di-nucleotide (41.62%). AT/TA and AAT/TTA were the main types of motif in di-, tri-nucleotide repeats. The repeat numbers of SSRs which from S. mussotii transcriptome SSRs were mainly from 5 to 10 and motif length of them mostly ranged from 12 bp to 30 bp. A total of 30 651 contigs were annotated, and only 1 447 SSRs were occurred in protein-coding regions. In the six repeat motifs, tri-nucleotide repeats were the most abundant in coding regions (928). There are abundant SSRs in S. mussotii transcriptome with high frequency and various types, indicating their usefulness in theory. This research may lay the foundation for designing the targeted SSR primers and developing SSR molecular markers by mining the information of SSRs loci in S. mussotii transcriptome sequences data.